What has produced higher life expectancy and lower death rate?
Improvements in medicine, agriculture, and living conditions.
What have scientists been focusing on to increase food supply?
Genetic engineering.
What are some new ways scientists are looking to power cars and other vehicles?
Batteries, solar power, and fuel cells.
What are some things that depend on fossil fuels?
Cars, stoves.
What source of energy does not cause air pollution?
Nuclear power.
How many people are born and die every second today?
4.2 are born and 1.8 die
What do we call microscopic structures found in the cells of every living thing?
Genes.
What takes longer than refilling a gasoline tank?
Recharging a battery.
What is Earth's most valuable fossil fuel?
Oil, natural gas, and coal.
Where are wind farms?
On treeless hills.
What are some of Earth's limited resources?
Food, water, and fossil fuels.
What kills weeds?
Herbicides.
What cars run on a combination of electricity and gasoline?
Hybrid cars.
What are some things we can do to preserve fossil fuels?
Riding a bicycle to school, recycling.
What is the source of the energy that we use?
Fuel.
What led to water and air pollution?
Lack of knowledge and limited technologies.
What chemicals do people use to produce stronger and bigger crops?
Fertilizers, herbicides, and pesticides.
What do solar-powered cars get energy from?
The sun.
How do we use energy?
We turn on bedroom lights, use a computer, or ride a car.
How do environmentally friendly buildings cool buildings efficiently?
Sunlight and ventilation.
How have scientists developed ways to reduce air and water pollution?
Thanks to government regulations and industry efforts.
What are some dangers of chemicals?
They hurt the environment (kill insects that do not harm crops or hurt animals).
What two gases do hydrogen-powered cars combine to produce electricity?
Hydrogen and oxygen.
What can be dangerous if disposed of improperly?
Unwanted leftover material from nuclear plants.
What do mirrors from solar panels focus on?
Large containers of water.